Can Wikipedia written content and images be used on my website, without a direct recognition on the page it is used. Perhaps place any thanks/recognition in the terms and conditions of my page.
You can use all the text, and most of the images, under some conditions, and those conditions include proper attribution.
Wikipedias text is under the Creative Commons Attribution-Share Alike 3.0 license (CC BY-SA 3.0). If you abide by those conditions - that is, credit the writers, and publish the text (or whatever adaptations you've made to the text) under the same licence, you can use it on your website.
The conditions entail attribution. The relevant (abridged, emphasis mine) text from the license (clause 4c) reads:
If You Distribute [...] the Work [...], You must [...] keep intact all copyright notices for the Work and provide, reasonable to the medium or means You are utilizing: (i) the name of the Original Author [...] (ii) the title of the Work if supplied; (iii) to the extent reasonably practicable, the URI, if any, that Licensor specifies to be associated with the Work [...] and (iv) , [...] in the case of an Adaptation, a credit identifying the use of the Work in the Adaptation (e.g., "French translation of the Work by Original Author," or "Screenplay based on original Work by Original Author"). The credit required by this Section 4(c) may be implemented in any reasonable manner; provided, however, that in the case of a Adaptation or Collection, at a minimum such credit will appear, if a credit for all contributing authors of the Adaptation or Collection appears, then as part of these credits and in a manner at least as prominent as the credits for the other contributing authors. [...]
This means you are at least required to put in a notice for every article you use. This would, if nothing else, make it entirely impractical to put it in a single copyright notice file.
There is a guide for re-use hosted on Wikipedia, which gives more details on how you should attribute the material, and how to attach a license. It advices to provide a link to the articles history next to the material.
Common sense would dictate you follow the re-use guides of Wikipedia, which stipulate you have something like the following near the text (a footer maybe?)
This article uses material from the Wikipedia article "Metasyntactic variable", which is released under the Creative Commons Attribution-Share-Alike License 3.0.
If you choose to not follow Wikipedias guide to re-use, but dump everything in a single terms you might be good, or you might be in violation of the license, but that would be for a court to decide on; this hasn't been tested before.
Between the impracticality, the possibly illegality, and the fact that pushing proper attribution of the writers of the material to some backwater is a bit of a dick move, I'd really advice just going with the recommended guide.
The images you see on Wikipedia are partially free, under the same license or more permissive as the text, and partially non-free with a fair use defense. What counts as fair use for Wikipedia doesn't necessarily count as fair use for you. You should check per image: if you click on any image it will show you its licensing details.
Any image that is hosted on Wikimedia Commons is under a free license. This is the majority of images and other media on Wikipedia.
Some of those images might still be problematic in some countries: for example, works from the US government are in the public domain only in the US. Freedom of panorama also differs significantly from country to country. Check per image if it's ok to use for you.